The concept of extension jambs for window and door frames is old in the art. Typically, extension jambs are used to extend the window or door frame to accommodate different wall thicknesses in a building. Frequently, the extension jambs are toe-nailed onto the window frame or, if not toe-nailed, attached through a hole drilled laterally through the entire extension jamb and a nail driven through the extension jamb to hold it in place. Both of these procedures are disadvantageous because they are not only time-consuming but the process can split or damage the extension jamb. In addition, nailing makes it difficult, if not impossible, to remove the extension jamb without damaging either the jamb or the frame if building construction requires removal of the extension.
The present invention improves the procedure by providing an extension jamb that caries a fastener in a ready-to-use, out of the way position to enable an on-site worker to attach the extension jambs to building frames quickly, such as doors, window frames and the like.